Integrated doherty power amplifier

ABSTRACT

Integrated Doherty power amplifiers are provided herein. In certain implementations, a Doherty power amplifier includes a carrier amplification stage that generates a carrier signal, a peaking amplification stage that generates a peaking signal, and an antenna structure that combines the carrier signal and the peaking signal. The antenna structure radiates a transmit wave in which the carrier signal and the peaking signal are combined with a phase shift.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119 ofU.S. Provisional Patent Application No. 62/685,489, filed Jun. 15, 2018and titled “INTEGRATED DOHERTY POWER AMPLIFIER,” which is hereinincorporated by reference in its entirety.

BACKGROUND Technical Field

Embodiments of the invention relate to electronic systems, and inparticular, to radio frequency (RF) electronics.

Description of Related Technology

A communication system can include a transceiver, a front end, and oneor more antennas for wirelessly transmitting and/or receiving signals.The front end can include low noise amplifier(s) for amplifyingrelatively weak signals received via the antenna(s), and poweramplifier(s) for boosting signals for transmission via the antenna(s).

Examples of communication systems include, but are not limited to,mobile phones, tablets, base stations, network access points,customer-premises equipment (CPE), laptops, and wearable electronics.

SUMMARY

In certain embodiments, the present disclosure relates to an integratedDoherty power amplifier. The integrated Doherty power amplifier includesa splitting and phase shifting circuit configured to receive a radiofrequency input signal, and to output a first radio frequency signal anda second radio frequency signal. The integrated Doherty power amplifierfurther includes a carrier amplification stage configured to generate acarrier signal based on amplifying the first radio frequency signal, apeaking amplification stage configured to generate a peaking signalbased on amplifying the second radio frequency signal, and an antennastructure configured to combine the carrier signal and the peakingsignal, and to radiate a transmit wave in which the carrier signal andthe peaking signal are combined with a phase shift.

In several embodiments, the antenna structure provides the phase shift.

In a number of embodiments, the integrated Doherty power amplifierfurther includes an output phase shifter configured to provide at leasta portion of the phase shift.

In various embodiments, the first radio frequency signal and the secondradio frequency signal have about equal power and a phase difference ofabout ninety degrees.

In some embodiments, the antenna structure includes a first portconfigured to receive the carrier signal and a second port configured toreceive the peaking signal. According to several embodiments, thecarrier amplification stage matches into an impedance of the first port,and the peaking amplification stage matches into an impedance of thesecond port. In accordance with a number of embodiments, the first portprovides a first impedance transformation, and the second port providesa second impedance transformation different from the first impedancetransformation. According to various embodiments, the antenna structureincludes a patch antenna element, and an impedance transformer includinga feed conductor coupled to the patch antenna element, a first inputconductor extending from the feed conductor and including the firstport, and a second input conductor extending from the feed conductor andincluding the second port. In accordance with several embodiments, theantenna structure includes a patch antenna element, and an impedancetransformer having a first metal region and a second metal region ofdifferent widths, the second metal region connecting the first metalregion to the patch antenna element. According to a number ofembodiments, the first metal region includes the first port and thesecond port, the second metal region of narrower width than the firstmetal region. In accordance with a various embodiments, a distancebetween the first port and the second port provides a phase shift ofabout ninety degrees at a frequency of the transmit wave.

In certain embodiments, the present disclosure relates to a mobiledevice. The mobile device includes a transceiver configured to generatea radio frequency input signal, and a Doherty power amplifier configuredto amplify the radio frequency input signal. The Doherty power amplifierincludes a carrier amplification stage configured to output a carriersignal and a peaking amplification stage configured to output a peakingsignal. The mobile device further includes an antenna structureconfigured to combine the carrier signal and the peaking signal, and toradiate a transmit wave in which the carrier signal and the peakingsignal are combined with a phase shift.

In some embodiments, the antenna structure includes a first portconfigured to receive the carrier signal and a second port configured toreceive the peaking signal. According to a number of embodiments, thefirst port provides a first impedance transformation, and the secondport provides a second impedance transformation different from the firstimpedance transformation. In accordance with several embodiments, theantenna structure includes a patch antenna element, and an impedancetransformer including a feed conductor coupled to the patch antennaelement, a first input conductor extending from the feed conductor andincluding the first port, and a second input conductor extending fromthe feed conductor and including the second port. According to variousembodiments, the antenna structure includes a patch antenna element, andan impedance transformer having a first metal region and a second metalregion of different widths, the second metal region connecting the firstmetal region to the patch antenna element. In accordance with a numberof embodiments, the impedance transformer includes a first metal regionand a second metal region of different widths, the second metal regionconnecting the first metal region to the patch antenna element, and thefirst metal region including the first port and the second port.

In certain embodiments, the present disclosure relates to a radiofrequency module. The radio frequency module includes a substrate, and asemiconductor die attached to the substrate and including a Dohertypower amplifier configured to amplify a radio frequency input signal.The Doherty power amplifier includes a carrier amplification stageconfigured to generate a carrier signal and a peaking amplificationstage configured to generate a peaking signal. The radio frequencymodule further includes an antenna structure attached to the substrateand configured to combine the carrier signal and the peaking signal, theantenna structure configured to radiate a transmit wave in which thecarrier signal and the peaking signal are combined with a phase shift.

In various embodiments, the antenna structure includes a first portconfigured to receive the carrier signal and a second port configured toreceive the peaking signal. According to a number of embodiments, thefirst port provides a first impedance transformation, and the secondport provides a second impedance transformation different from the firstimpedance transformation.

In certain embodiments, the present disclosure relates to an integratedDoherty power amplifier. The integrated Doherty power amplifier includesa carrier amplification stage configured to generate a carrier signalbased on amplifying a first radio frequency signal, a peakingamplification stage configured to generate a peaking signal based onamplifying a second radio frequency signal, and an antenna including afirst port configured to receive the carrier signal and a second portconfigured to receive the peaking signal, the antenna configured toradiate a transmit wave in which the carrier signal and the peakingsignal are combined with a phase shift.

In a number of embodiments, the phase shift is about ninety degrees.

In various embodiments, the carrier amplification stage matches into animpedance of the first port.

In several embodiments, the peaking amplification stage matches into animpedance of the second port.

In some embodiments, the first port provides a first impedancetransformation, and the second port provides a second impedancetransformation different from the first impedance transformation.

In various embodiments, the integrated Doherty power amplifier furtherincludes a splitter and phase shifter configured to receive a radiofrequency input signal, and to output the first radio frequency signaland the second radio frequency signal.

In a number of embodiments, the integrated Doherty power amplifier isimplemented in an antenna array.

In some embodiments, the first radio frequency signal and the secondradio frequency signal have about equal power and a phase difference ofabout ninety degrees.

In various embodiments, the antenna comprises a patch antenna, a dipoleantenna, a ceramic resonator antenna, a stamped metal antenna, or alaser direct structuring antenna.

In some embodiments, the antenna includes an impedance transformercoupled to a patch antenna element, the impedance transformer includingthe first port and the second port. According to a number ofembodiments, the impedance transformer includes a first metal region anda second metal region of different widths, the second metal regionconnecting the first metal region to the patch antenna element. Inaccordance with various embodiments, the first metal region includes thefirst port and the second port. According to several embodiments, thesecond metal region is of narrower width than the first metal region. Inaccordance with a number of embodiments, a distance between the firstport and the second port provides a phase shift of about ninety degreesat a frequency of the transmit wave. According to various embodiments,the impedance transformer further includes a ground plane beneath atleast a portion of the patch antenna element and/or the impedancetransformer. In accordance with several embodiments, the impedancetransformer includes a feed conductor coupled to the patch antennaelement. According to a number of embodiments, the impedance transformfurther includes a first input conductor extending from the feedconductor and including the first port. In accordance with variousembodiments, the impedance transformer further includes a metal stubextending from the first input conductor. According to severalembodiments, the impedance transformer further includes a second inputconductor extending from the feed conductor and including the secondport. In accordance with a number of embodiments, the impedancetransformer further includes a first metal stub extending form the firstinput conductor and a second metal stub extending from the second inputconductor. According to various embodiments, the first input conductorand the second input conductor are of different lengths. In accordancewith several embodiments, the first input conductor and the second inputconductor are on opposite sides of the feed conductor. According to anumber of embodiments, the integrated Doherty power amplifier furtherincludes a ground plane, the impedance transformer positioned betweenthe patch antenna element and the ground plane.

In certain embodiments, the present disclosure relates to a mobiledevice. The mobile device includes a transceiver configured to generatea radio frequency input signal. The mobile device further includes aDoherty power amplifier configured to amplify the radio frequency inputsignal, the Doherty power amplifier including a carrier amplificationstage configured to generate a carrier signal and a peakingamplification stage configured to generate a peaking signal. The mobiledevice further includes an antenna including a first port configured toreceive the carrier signal and a second port configured to receive thepeaking signal, the antenna configured to radiate a transmit wave inwhich the carrier signal and the peaking signal are combined with aphase shift.

In a number of embodiments, the phase shift is about ninety degrees.

In various embodiments, the carrier amplification stage matches into animpedance of the first port.

In several embodiments, the peaking amplification stage matches into animpedance of the second port.

In some embodiments, the first port provides a first impedancetransformation, and the second port provides a second impedancetransformation different from the first impedance transformation.

In various embodiments, the Doherty power amplifier further includes asplitter and phase shifter configured to receive a radio frequency inputsignal, and to output the first radio frequency signal and the secondradio frequency signal.

In some embodiments, the first radio frequency signal and the secondradio frequency signal have about equal power and a phase difference ofabout ninety degrees.

In various embodiments, the antenna comprises a patch antenna, a dipoleantenna, a ceramic resonator antenna, a stamped metal antenna, or alaser direct structuring antenna.

In some embodiments, the antenna includes an impedance transformercoupled to a patch antenna element, the impedance transformer includingthe first port and the second port. According to a number ofembodiments, the impedance transformer includes a first metal region anda second metal region of different widths, the second metal regionconnecting the first metal region to the patch antenna element. Inaccordance with various embodiments, the first metal region includes thefirst port and the second port. According to several embodiments, thesecond metal region is of narrower width than the first metal region. Inaccordance with a number of embodiments, a distance between the firstport and the second port provides a phase shift of about ninety degreesat a frequency of the transmit wave. According to various embodiments,the impedance transformer further includes a ground plane beneath atleast a portion of the patch antenna element and/or the impedancetransformer. In accordance with several embodiments, the impedancetransformer includes a feed conductor coupled to the patch antennaelement. According to a number of embodiments, the impedance transformfurther includes a first input conductor extending from the feedconductor and including the first port. In accordance with variousembodiments, the impedance transformer further includes a metal stubextending from the first input conductor. According to severalembodiments, the impedance transformer further includes a second inputconductor extending from the feed conductor and including the secondport. In accordance with a number of embodiments, the impedancetransformer further includes a first metal stub extending form the firstinput conductor and a second metal stub extending from the second inputconductor. According to various embodiments, the first input conductorand the second input conductor are of different lengths. In accordancewith several embodiments, the first input conductor and the second inputconductor are on opposite sides of the feed conductor. According to anumber of embodiments, the Doherty power amplifier further includes aground plane, the impedance transformer positioned between the patchantenna element and the ground plane.

In certain embodiments, the present disclosure relates to a radiofrequency module. The radio frequency module includes a substrate, and asemiconductor die attached to the substrate and including a Dohertypower amplifier configured to amplify a radio frequency input signal.The Doherty power amplifier includes a carrier amplification stageconfigured to generate a carrier signal and a peaking amplificationstage configured to generate a peaking signal. The radio frequencymodule further includes an antenna including a first port configured toreceive the carrier signal and a second port configured to receive thepeaking signal, the antenna configured to radiate a transmit wave inwhich the carrier signal and the peaking signal are combined with aphase shift.

In a number of embodiments, the phase shift is about ninety degrees.

In various embodiments, the carrier amplification stage matches into animpedance of the first port.

In several embodiments, the peaking amplification stage matches into animpedance of the second port.

In some embodiments, the first port provides a first impedancetransformation, and the second port provides a second impedancetransformation different from the first impedance transformation.

In various embodiments, the Doherty power amplifier further includes asplitter and phase shifter configured to receive a radio frequency inputsignal, and to output the first radio frequency signal and the secondradio frequency signal.

In some embodiments, the first radio frequency signal and the secondradio frequency signal have about equal power and a phase difference ofabout ninety degrees.

In various embodiments, the antenna comprises a patch antenna, a dipoleantenna, a ceramic resonator antenna, a stamped metal antenna, or alaser direct structuring antenna.

In various embodiments, the antenna is integrated with the substrate.

In some embodiments, the antenna includes an impedance transformercoupled to a patch antenna element, the impedance transformer includingthe first port and the second port. According to a number ofembodiments, the impedance transformer includes a first metal region anda second metal region of different widths, the second metal regionconnecting the first metal region to the patch antenna element. Inaccordance with various embodiments, the first metal region includes thefirst port and the second port. According to several embodiments, thesecond metal region is of narrower width than the first metal region. Inaccordance with a number of embodiments, a distance between the firstport and the second port provides a phase shift of about ninety degreesat a frequency of the transmit wave. According to various embodiments,the impedance transformer further includes a ground plane beneath atleast a portion of the patch antenna element and/or the impedancetransformer. In accordance with several embodiments, the impedancetransformer includes a feed conductor coupled to the patch antennaelement. According to a number of embodiments, the impedance transformfurther includes a first input conductor extending from the feedconductor and including the first port. In accordance with variousembodiments, the impedance transformer further includes a metal stubextending from the first input conductor. According to severalembodiments, the impedance transformer further includes a second inputconductor extending from the feed conductor and including the secondport. In accordance with a number of embodiments, the impedancetransformer further includes a first metal stub extending form the firstinput conductor and a second metal stub extending from the second inputconductor. According to various embodiments, the first input conductorand the second input conductor are of different lengths. In accordancewith several embodiments, the first input conductor and the second inputconductor are on opposite sides of the feed conductor. According to anumber of embodiments, the Doherty power amplifier further includes aground plane, the impedance transformer positioned between the patchantenna element and the ground plane.

In certain embodiments, an integrated Doherty power amplifier isprovided. The integrated Doherty power amplifier includes a carrieramplification stage configured to generate a carrier signal based onamplifying a first radio frequency signal, a peaking amplification stageconfigured to generate a peaking signal based on amplifying a secondradio frequency signal, a first antenna including a first portconfigured to receive the carrier signal, and a second antenna includinga second port configured to receive the peaking signal. The firstantenna and the second antenna are configured to operate in combinationwith one another to radiate a transmit wave in which the carrier signaland the peaking signal are combined with a phase shift.

In a number of embodiments, the phase shift is about ninety degrees.

In various embodiments, the carrier amplification stage matches into animpedance of the first port.

In several embodiments, the peaking amplification stage matches into animpedance of the second port.

In some embodiments, the first port provides a first impedancetransformation, and the second port provides a second impedancetransformation different from the first impedance transformation.

In various embodiments, the integrated Doherty power amplifier furtherincludes a splitter and phase shifter configured to receive a radiofrequency input signal, and to output the first radio frequency signaland the second radio frequency signal.

In a number of embodiments, the integrated Doherty power amplifier isimplemented in an antenna array.

In some embodiments, the first radio frequency signal and the secondradio frequency signal have about equal power and a phase difference ofabout ninety degrees.

In various embodiments, the antenna comprises a patch antenna, a dipoleantenna, a ceramic resonator antenna, a stamped metal antenna, or alaser direct structuring antenna.

In a number of embodiments, the first antenna radiates a first wave andthe second antenna radiates a second wave, the first wave and the secondwave configured to combine by constructive interference to generate thetransmit wave. According to several embodiments, the first wave and thesecond wave are configured to combine in the far field to provide thephase shift.

In some embodiments, the first antenna and the second antenna eachcomprise a patch antenna, a dipole antenna, a ceramic resonator antenna,a stamped metal antenna, or a laser direct structuring antenna.

In certain embodiments, the present disclosure relates to a mobiledevice including a transceiver configured to generate a radio frequencyinput signal, and a Doherty power amplifier configured to amplify theradio frequency input signal. The Doherty power amplifier includes acarrier amplification stage configured to generate a carrier signal anda peaking amplification stage configured to generate a peaking signal.The mobile device further includes a first antenna including a firstport configured to receive the carrier signal, and a second antennaincluding a second port configured to receive the peaking signal. Thefirst antenna and the second antenna are configured to operate incombination with one another to radiate a transmit wave in which thecarrier signal and the peaking signal are combined with a phase shift.

In a number of embodiments, the phase shift is about ninety degrees.

In various embodiments, the carrier amplification stage matches into animpedance of the first port.

In several embodiments, the peaking amplification stage matches into animpedance of the second port.

In some embodiments, the first port provides a first impedancetransformation, and the second port provides a second impedancetransformation different from the first impedance transformation.

In various embodiments, the Doherty power amplifier further includes asplitter and phase shifter configured to receive a radio frequency inputsignal, and to output the first radio frequency signal and the secondradio frequency signal.

In some embodiments, the first radio frequency signal and the secondradio frequency signal have about equal power and a phase difference ofabout ninety degrees.

In a number of embodiments, the first antenna radiates a first wave andthe second antenna radiates a second wave, and the first wave and thesecond wave are configured to combine by constructive interference togenerate the transmit wave. According to a number of embodiments, thefirst wave and the second wave are configured to combine in the farfield to provide the phase shift.

In several embodiments, the first antenna and the second antenna eachcomprise a patch antenna, a dipole antenna, a ceramic resonator antenna,a stamped metal antenna, or a laser direct structuring antenna.

In certain embodiments, the present disclosure relates to a radiofrequency module. The radio frequency module includes a substrate, and asemiconductor die attached to the substrate and including a Dohertypower amplifier configured to amplify a radio frequency input signal.The Doherty power amplifier includes a carrier amplification stageconfigured to generate a carrier signal and a peaking amplificationstage configured to generate a peaking signal. The radio frequencymodule further includes an antenna including a first port configured toreceive the carrier signal and a second port configured to receive thepeaking signal, the antenna configured to radiate a transmit wave inwhich the carrier signal and the peaking signal are combined with aphase shift.

In a number of embodiments, the phase shift is about ninety degrees.

In various embodiments, the carrier amplification stage matches into animpedance of the first port.

In several embodiments, the peaking amplification stage matches into animpedance of the second port.

In some embodiments, the first port provides a first impedancetransformation, and the second port provides a second impedancetransformation different from the first impedance transformation.

In various embodiments, the Doherty power amplifier further includes asplitter and phase shifter configured to receive a radio frequency inputsignal, and to output the first radio frequency signal and the secondradio frequency signal.

In some embodiments, the first radio frequency signal and the secondradio frequency signal have about equal power and a phase difference ofabout ninety degrees.

In certain embodiments, the first antenna radiates a first wave and thesecond antenna radiates a second wave, and the first wave and the secondwave are configured to combine by constructive interference to generatethe transmit wave. According to a number of embodiments, the first waveand the second wave are configured to combine in the far field toprovide the phase shift.

In various embodiments, the first antenna and the second antenna eachcomprise a patch antenna, a dipole antenna, a ceramic resonator antenna,a stamped metal antenna, or a laser direct structuring antenna.

In several embodiments, the first antenna and the second antenna areintegrated with the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this disclosure will now be described, by way ofnon-limiting example, with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of one example of a communication network.

FIG. 2A is a schematic diagram of one example of a communication linkusing carrier aggregation.

FIG. 2B illustrates various examples of uplink carrier aggregation forthe communication link of FIG. 2A.

FIG. 2C illustrates various examples of downlink carrier aggregation forthe communication link of FIG. 2A.

FIG. 3A is a schematic diagram of one example of a downlink channelusing multi-input and multi-output (MIMO) communications.

FIG. 3B is schematic diagram of one example of an uplink channel usingMIMO communications.

FIG. 3C is schematic diagram of another example of an uplink channelusing MIMO communications.

FIG. 4A is a schematic diagram of one example of a communication systemthat operates with beamforming.

FIG. 4B is a schematic diagram of one example of beamforming to providea transmit beam.

FIG. 4C is a schematic diagram of one example of beamforming to providea receive beam.

FIG. 5 is a schematic diagram of an integrated Doherty power amplifieraccording to one embodiment.

FIG. 6A is a schematic diagram of an integrated Doherty power amplifieraccording to another embodiment.

FIG. 6B is a schematic diagram of an integrated Doherty power amplifieraccording to another embodiment.

FIG. 6C is a schematic diagram of an integrated Doherty power amplifieraccording to another embodiment.

FIG. 6D is a schematic diagram of an integrated Doherty power amplifieraccording to another embodiment.

FIG. 6E is a schematic diagram of an integrated Doherty power amplifieraccording to another embodiment.

FIG. 6F is a schematic diagram of an integrated Doherty power amplifieraccording to another embodiment.

FIG. 7A is an impedance model of a multi-feed patch antenna according toone embodiment.

FIG. 7B is one example of a Smith chart of S11 for the multi-feed patchantenna of FIG. 7A.

FIG. 7C is one example of a Smith chart of S22 for the multi-feed patchantenna of FIG. 7A.

FIG. 7D is a graph of one example of isolation versus frequency for themulti-feed patch antenna of FIG. 7A.

FIG. 7E is a graph of one example of phase shift versus frequency forthe multi-feed patch antenna of FIG. 7A.

FIG. 8A is a perspective view of a patch antenna with impedancetransformer according to one embodiment.

FIG. 8B is a schematic diagram of a radiation pattern for the patchantenna with impedance transformer of FIG. 8A.

FIG. 9A is an impedance model of the patch antenna with impedancetransformer of FIG. 8A according to one embodiment.

FIG. 9B is one example of a Smith chart of S11 for the patch antennawith impedance transformer of FIG. 8A.

FIG. 9C is one example of a Smith chart of S22 for the patch antennawith impedance transformer of FIG. 9A.

FIG. 9D is a graph of one example of isolation versus frequency for thepatch antenna with impedance transformer of FIG. 8A.

FIG. 9E is a graph of one example of phase shift versus frequency forthe patch antenna with impedance transformer of FIG. 8A.

FIG. 10A is a perspective view of a multi-feed patch antenna accordingto one embodiment.

FIG. 10B is a plan view of the impedance transformer of FIG. 10A.

FIG. 10C is a schematic diagram of a radiation pattern for themulti-feed patch antenna of FIG. 10A.

FIG. 11A is one example of a Smith chart of S11 for the multi-feed patchantenna of FIG. 10A.

FIG. 11B is one example of a Smith chart of S22 for the multi-feed patchantenna of FIG. 10A.

FIG. 11C is a graph of one example of isolation versus frequency for themulti-feed patch antenna of FIG. 10A.

FIG. 11D is a graph of one example of phase shift versus frequency forthe multi-feed patch antenna of FIG. 10A.

FIG. 12 is a schematic diagram of one embodiment of a module.

FIG. 13A is a perspective view of another embodiment of a module.

FIG. 13B is a cross-section of the module of FIG. 13A taken along thelines 13B-13B.

FIG. 14 is a schematic diagram of one embodiment of a mobile device.

FIG. 15 is a schematic diagram of a power amplifier system according toone embodiment.

FIG. 16A is a schematic diagram of another embodiment of a module.

FIG. 16B is a schematic diagram of a cross-section of the module of FIG.16A taken along the lines 16B-16B.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The following detailed description of certain embodiments presentsvarious descriptions of specific embodiments. However, the innovationsdescribed herein can be embodied in a multitude of different ways, forexample, as defined and covered by the claims. In this description,reference is made to the drawings where like reference numerals canindicate identical or functionally similar elements. It will beunderstood that elements illustrated in the figures are not necessarilydrawn to scale. Moreover, it will be understood that certain embodimentscan include more elements than illustrated in a drawing and/or a subsetof the elements illustrated in a drawing. Further, some embodiments canincorporate any suitable combination of features from two or moredrawings.

The International Telecommunication Union (ITU) is a specialized agencyof the United Nations (UN) responsible for global issues concerninginformation and communication technologies, including the shared globaluse of radio spectrum.

The 3rd Generation Partnership Project (3GPP) is a collaboration betweengroups of telecommunications standard bodies across the world, such asthe Association of Radio Industries and Businesses (ARIB), theTelecommunications Technology Committee (TTC), the China CommunicationsStandards Association (CCSA), the Alliance for TelecommunicationsIndustry Solutions (ATIS), the Telecommunications Technology Association(TTA), the European Telecommunications Standards Institute (ETSI), andthe Telecommunications Standards Development Society, India (TSDSI).

Working within the scope of the ITU, 3GPP develops and maintainstechnical specifications for a variety of mobile communicationtechnologies, including, for example, second generation (2G) technology(for instance, Global System for Mobile Communications (GSM) andEnhanced Data Rates for GSM Evolution (EDGE)), third generation (3G)technology (for instance, Universal Mobile Telecommunications System(UMTS) and High Speed Packet Access (HSPA)), and fourth generation (4G)technology (for instance, Long Term Evolution (LTE) and LTE-Advanced).

The technical specifications controlled by 3GPP can be expanded andrevised by specification releases, which can span multiple years andspecify a breadth of new features and evolutions.

In one example, 3GPP introduced carrier aggregation (CA) for LTE inRelease 10. Although initially introduced with two downlink carriers,3GPP expanded carrier aggregation in Release 14 to include up to fivedownlink carriers and up to three uplink carriers. Other examples of newfeatures and evolutions provided by 3GPP releases include, but are notlimited to, License Assisted Access (LAA), enhanced LAA (eLAA),Narrowband Internet of things (NB-IOT), Vehicle-to-Everything (V2X), andHigh Power User Equipment (HPUE).

3GPP introduced Phase 1 of fifth generation (5G) technology in Release15, and plans to introduce Phase 2 of 5G technology in Release 16(targeted for 2019). Subsequent 3GPP releases will further evolve andexpand 5G technology. 5G technology is also referred to herein as 5G NewRadio (NR).

5G NR supports or plans to support a variety of features, such ascommunications over millimeter wave spectrum, beamforming capability,high spectral efficiency waveforms, low latency communications, multipleradio numerology, and/or non-orthogonal multiple access (NOMA). Althoughsuch RF functionalities offer flexibility to networks and enhance userdata rates, supporting such features can pose a number of technicalchallenges.

The teachings herein are applicable to a wide variety of communicationsystems, including, but not limited to, communication systems usingadvanced cellular technologies, such as LTE-Advanced, LTE-Advanced Pro,and/or 5G NR.

FIG. 1 is a schematic diagram of one example of a communication network10. The communication network 10 includes a macro cell base station 1, asmall cell base station 3, and various examples of user equipment (UE),including a first mobile device 2 a, a wireless-connected car 2 b, alaptop 2 c, a stationary wireless device 2 d, a wireless-connected train2 e, a second mobile device 2 f, and a third mobile device 2 g.

Although specific examples of base stations and user equipment areillustrated in FIG. 1, a communication network can include base stationsand user equipment of a wide variety of types and/or numbers.

For instance, in the example shown, the communication network 10includes the macro cell base station 1 and the small cell base station3. The small cell base station 3 can operate with relatively lowerpower, shorter range, and/or with fewer concurrent users relative to themacro cell base station 1. The small cell base station 3 can also bereferred to as a femtocell, a picocell, or a microcell. Although thecommunication network 10 is illustrated as including two base stations,the communication network 10 can be implemented to include more or fewerbase stations and/or base stations of other types.

Although various examples of user equipment are shown, the teachingsherein are applicable to a wide variety of user equipment, including,but not limited to, mobile phones, tablets, laptops, IoT devices,wearable electronics, customer premises equipment (CPE),wireless-connected vehicles, wireless relays, and/or a wide variety ofother communication devices. Furthermore, user equipment includes notonly currently available communication devices that operate in acellular network, but also subsequently developed communication devicesthat will be readily implementable with the inventive systems,processes, methods, and devices as described and claimed herein.

The illustrated communication network 10 of FIG. 1 supportscommunications using a variety of cellular technologies, including, forexample, 4G LTE and 5G NR. In certain implementations, the communicationnetwork 10 is further adapted to provide a wireless local area network(WLAN), such as WiFi. Although various examples of communicationtechnologies have been provided, the communication network 10 can beadapted to support a wide variety of communication technologies.

Various communication links of the communication network 10 have beendepicted in FIG. 1. The communication links can be duplexed in a widevariety of ways, including, for example, using frequency-divisionduplexing (FDD) and/or time-division duplexing (TDD). FDD is a type ofradio frequency communications that uses different frequencies fortransmitting and receiving signals. FDD can provide a number ofadvantages, such as high data rates and low latency. In contrast, TDD isa type of radio frequency communications that uses about the samefrequency for transmitting and receiving signals, and in which transmitand receive communications are switched in time. TDD can provide anumber of advantages, such as efficient use of spectrum and variableallocation of throughput between transmit and receive directions.

In certain implementations, user equipment can communicate with a basestation using one or more of 4G LTE, 5G NR, and WiFi technologies. Incertain implementations, enhanced license assisted access (eLAA) is usedto aggregate one or more licensed frequency carriers (for instance,licensed 4G LTE and/or 5G NR frequencies), with one or more unlicensedcarriers (for instance, unlicensed WiFi frequencies).

As shown in FIG. 1, the communication links include not onlycommunication links between UE and base stations, but also UE to UEcommunications and base station to base station communications. Forexample, the communication network 10 can be implemented to supportself-fronthaul and/or self-backhaul (for instance, as between mobiledevice 2 g and mobile device 2 f).

The communication links can operate over a wide variety of frequencies.In certain implementations, communications are supported using 5G NRtechnology over one or more frequency bands that are less than 6Gigahertz (GHz) and/or over one or more frequency bands that are greaterthan 6 GHz. For example, the communication links can serve FrequencyRange 1 (FR1), Frequency Range 2 (FR2), or a combination thereof. In oneembodiment, one or more of the mobile devices support a HPUE power classspecification.

In certain implementations, a base station and/or user equipmentcommunicates using beamforming. For example, beamforming can be used tofocus signal strength to overcome path losses, such as high lossassociated with communicating over high signal frequencies. In certainembodiments, user equipment, such as one or more mobile phones,communicate using beamforming on millimeter wave frequency bands in therange of 30 GHz to 300 GHz and/or upper centimeter wave frequencies inthe range of 6 GHz to 30 GHz, or more particularly, 24 GHz to 30 GHz.

Different users of the communication network 10 can share availablenetwork resources, such as available frequency spectrum, in a widevariety of ways.

In one example, frequency division multiple access (FDMA) is used todivide a frequency band into multiple frequency carriers. Additionally,one or more carriers are allocated to a particular user. Examples ofFDMA include, but are not limited to, single carrier FDMA (SC-FDMA) andorthogonal FDMA (OFDMA). OFDMA is a multicarrier technology thatsubdivides the available bandwidth into multiple mutually orthogonalnarrowband subcarriers, which can be separately assigned to differentusers.

Other examples of shared access include, but are not limited to, timedivision multiple access (TDMA) in which a user is allocated particulartime slots for using a frequency resource, code division multiple access(CDMA) in which a frequency resource is shared amongst different usersby assigning each user a unique code, space-divisional multiple access(SDMA) in which beamforming is used to provide shared access by spatialdivision, and non-orthogonal multiple access (NOMA) in which the powerdomain is used for multiple access. For example, NOMA can be used toserve multiple users at the same frequency, time, and/or code, but withdifferent power levels.

Enhanced mobile broadband (eMBB) refers to technology for growing systemcapacity of LTE networks. For example, eMBB can refer to communicationswith a peak data rate of at least 10 Gbps and a minimum of 100 Mbps foreach user. Ultra-reliable low latency communications (uRLLC) refers totechnology for communication with very low latency, for instance, lessthan 2 milliseconds. uRLLC can be used for mission-criticalcommunications such as for autonomous driving and/or remote surgeryapplications. Massive machine-type communications (mMTC) refers to lowcost and low data rate communications associated with wirelessconnections to everyday objects, such as those associated with Internetof Things (IoT) applications.

The communication network 10 of FIG. 1 can be used to support a widevariety of advanced communication features, including, but not limitedto, eMBB, uRLLC, and/or mMTC.

FIG. 2A is a schematic diagram of one example of a communication linkusing carrier aggregation. Carrier aggregation can be used to widenbandwidth of the communication link by supporting communications overmultiple frequency carriers, thereby increasing user data rates andenhancing network capacity by utilizing fragmented spectrum allocations.

In the illustrated example, the communication link is provided between abase station 21 and a mobile device 22. As shown in FIG. 2A, thecommunications link includes a downlink channel used for RFcommunications from the base station 21 to the mobile device 22, and anuplink channel used for RF communications from the mobile device 22 tothe base station 21.

Although FIG. 2A illustrates carrier aggregation in the context of FDDcommunications, carrier aggregation can also be used for TDDcommunications.

In certain implementations, a communication link can provideasymmetrical data rates for a downlink channel and an uplink channel.For example, a communication link can be used to support a relativelyhigh downlink data rate to enable high speed streaming of multimediacontent to a mobile device, while providing a relatively slower datarate for uploading data from the mobile device to the cloud.

In the illustrated example, the base station 21 and the mobile device 22communicate via carrier aggregation, which can be used to selectivelyincrease bandwidth of the communication link. Carrier aggregationincludes contiguous aggregation, in which contiguous carriers within thesame operating frequency band are aggregated. Carrier aggregation canalso be non-contiguous, and can include carriers separated in frequencywithin a common band or in different bands.

In the example shown in FIG. 2A, the uplink channel includes threeaggregated component carriers f_(UL1), f_(UL2), and f_(UL3).Additionally, the downlink channel includes five aggregated componentcarriers f_(DL1), f_(DL2), f_(DL3), f_(DL4), and f_(DL5). Although oneexample of component carrier aggregation is shown, more or fewercarriers can be aggregated for uplink and/or downlink. Moreover, anumber of aggregated carriers can be varied over time to achieve desireduplink and downlink data rates.

For example, a number of aggregated carriers for uplink and/or downlinkcommunications with respect to a particular mobile device can changeover time. For example, the number of aggregated carriers can change asthe device moves through the communication network and/or as networkusage changes over time.

FIG. 2B illustrates various examples of uplink carrier aggregation forthe communication link of FIG. 2A. FIG. 2B includes a first carrieraggregation scenario 31, a second carrier aggregation scenario 32, and athird carrier aggregation scenario 33, which schematically depict threetypes of carrier aggregation.

The carrier aggregation scenarios 31-33 illustrate different spectrumallocations for a first component carrier f_(UL1), a second componentcarrier f_(UL2), and a third component carrier f_(UL3). Although FIG. 2Bis illustrated in the context of aggregating three component carriers,carrier aggregation can be used to aggregate more or fewer carriers.Moreover, although illustrated in the context of uplink, the aggregationscenarios are also applicable to downlink.

The first carrier aggregation scenario 31 illustrates intra-bandcontiguous carrier aggregation, in which component carriers that areadjacent in frequency and in a common frequency band are aggregated. Forexample, the first carrier aggregation scenario 31 depicts aggregationof component carriers f_(UL1), f_(UL2), and f_(UL3) that are contiguousand located within a first frequency band BAND1.

With continuing reference to FIG. 2B, the second carrier aggregationscenario 32 illustrates intra-band non-continuous carrier aggregation,in which two or more components carriers that are non-adjacent infrequency and within a common frequency band are aggregated. Forexample, the second carrier aggregation scenario 32 depicts aggregationof component carriers f_(UL1), f_(UL2), and f_(UL3) that arenon-contiguous, but located within a first frequency band BAND1.

The third carrier aggregation scenario 33 illustrates inter-bandnon-contiguous carrier aggregation, in which component carriers that arenon-adjacent in frequency and in multiple frequency bands areaggregated. For example, the third carrier aggregation scenario 33depicts aggregation of component carriers f_(UL1) and f_(UL2) of a firstfrequency band BAND1 with component carrier f_(UL3) of a secondfrequency band BAND2.

FIG. 2C illustrates various examples of downlink carrier aggregation forthe communication link of FIG. 2A. The examples depict various carrieraggregation scenarios 34-38 for different spectrum allocations of afirst component carrier f_(DL1), a second component carrier f_(DL2), athird component carrier f_(DL3), a fourth component carrier f_(DL4), anda fifth component carrier f_(DL5). Although FIG. 2C is illustrated inthe context of aggregating five component carriers, carrier aggregationcan be used to aggregate more or fewer carriers. Moreover, althoughillustrated in the context of downlink, the aggregation scenarios arealso applicable to uplink.

The first carrier aggregation scenario 34 depicts aggregation ofcomponent carriers that are contiguous and located within the samefrequency band. Additionally, the second carrier aggregation scenario 35and the third carrier aggregation scenario 36 illustrates two examplesof aggregation that are non-contiguous, but located within the samefrequency band. Furthermore, the fourth carrier aggregation scenario 37and the fifth carrier aggregation scenario 38 illustrates two examplesof aggregation in which component carriers that are non-adjacent infrequency and in multiple frequency bands are aggregated. As a number ofaggregated component carriers increases, a complexity of possiblecarrier aggregation scenarios also increases.

With reference to FIGS. 2A-2C, the individual component carriers used incarrier aggregation can be of a variety of frequencies, including, forexample, frequency carriers in the same band or in multiple bands.Additionally, carrier aggregation is applicable to implementations inwhich the individual component carriers are of about the same bandwidthas well as to implementations in which the individual component carriershave different bandwidths.

Certain communication networks allocate a particular user device with aprimary component carrier (PCC) or anchor carrier for uplink and a PCCfor downlink. Additionally, when the mobile device communicates using asingle frequency carrier for uplink or downlink, the user devicecommunicates using the PCC. To enhance bandwidth for uplinkcommunications, the uplink PCC can be aggregated with one or more uplinksecondary component carriers (SCCs). Additionally, to enhance bandwidthfor downlink communications, the downlink PCC can be aggregated with oneor more downlink SCCs.

In certain implementations, a communication network provides a networkcell for each component carrier. Additionally, a primary cell canoperate using a PCC, while a secondary cell can operate using a SCC. Theprimary and secondary cells may have different coverage areas, forinstance, due to differences in frequencies of carriers and/or networkenvironment.

License assisted access (LAA) refers to downlink carrier aggregation inwhich a licensed frequency carrier associated with a mobile operator isaggregated with a frequency carrier in unlicensed spectrum, such asWiFi. LAA employs a downlink PCC in the licensed spectrum that carriescontrol and signaling information associated with the communicationlink, while unlicensed spectrum is aggregated for wider downlinkbandwidth when available. LAA can operate with dynamic adjustment ofsecondary carriers to avoid WiFi users and/or to coexist with WiFiusers. Enhanced license assisted access (eLAA) refers to an evolution ofLAA that aggregates licensed and unlicensed spectrum for both downlinkand uplink.

FIG. 3A is a schematic diagram of one example of a downlink channelusing multi-input and multi-output (MIMO) communications. FIG. 3B isschematic diagram of one example of an uplink channel using MIMOcommunications.

MIMO communications use multiple antennas for simultaneouslycommunicating multiple data streams over common frequency spectrum. Incertain implementations, the data streams operate with differentreference signals to enhance data reception at the receiver. MIMOcommunications benefit from higher SNR, improved coding, and/or reducedsignal interference due to spatial multiplexing differences of the radioenvironment.

MIMO order refers to a number of separate data streams sent or received.For instance, MIMO order for downlink communications can be described bya number of transmit antennas of a base station and a number of receiveantennas for UE, such as a mobile device. For example, two-by-two (2×2)DL MIMO refers to MIMO downlink communications using two base stationantennas and two UE antennas. Additionally, four-by-four (4×4) DL MIMOrefers to MIMO downlink communications using four base station antennasand four UE antennas.

In the example shown in FIG. 3A, downlink MIMO communications areprovided by transmitting using M antennas 43 a, 43 b, 43 c, . . . 43 mof the base station 41 and receiving using N antennas 44 a, 44 b, 44 c,. . . 44 n of the mobile device 42. Accordingly, FIG. 3A illustrates anexample of m×n DL MIMO.

Likewise, MIMO order for uplink communications can be described by anumber of transmit antennas of UE, such as a mobile device, and a numberof receive antennas of a base station. For example, 2×2 UL MIMO refersto MIMO uplink communications using two UE antennas and two base stationantennas. Additionally, 4×4 UL MIMO refers to MIMO uplink communicationsusing four UE antennas and four base station antennas.

In the example shown in FIG. 3B, uplink MIMO communications are providedby transmitting using N antennas 44 a, 44 b, 44 c, . . . 44 n of themobile device 42 and receiving using M antennas 43 a, 43 b, 43 c, . . .43 m of the base station 41. Accordingly, FIG. 3B illustrates an exampleof n×m UL MIMO.

By increasing the level or order of MIMO, bandwidth of an uplink channeland/or a downlink channel can be increased.

MIMO communications are applicable to communication links of a varietyof types, such as FDD communication links and TDD communication links.

FIG. 3C is schematic diagram of another example of an uplink channelusing MIMO communications. In the example shown in FIG. 3C, uplink MIMOcommunications are provided by transmitting using N antennas 44 a, 44 b,44 c, . . . 44 n of the mobile device 42. Additional a first portion ofthe uplink transmissions are received using M antennas 43 a 1, 43 b 1,43 c 1, . . . 43 m 1 of a first base station 41 a, while a secondportion of the uplink transmissions are received using M antennas 43 a2, 43 b 2, 43 c 2, . . . 43 m 2 of a second base station 41 b.Additionally, the first base station 41 a and the second base station 41b communication with one another over wired, optical, and/or wirelesslinks.

The MIMO scenario of FIG. 3C illustrates an example in which multiplebase stations cooperate to facilitate MIMO communications.

FIG. 4A is a schematic diagram of one example of a communication system110 that operates with beamforming. The communication system 110includes a transceiver 105, signal conditioning circuits 104 a 1, 104 a2 . . . 104 an, 104 b 1, 104 b 2 . . . 104 bn, 104 m 1, 104 m 2 . . .104 mn, and an antenna array 102 that includes antenna elements 103 a 1,103 a 2 . . . 103 an, 103 b 1, 103 b 2 . . . 103 bn, 103 m 1, 103 m 2 .. . 103 mn.

Communications systems that communicate using millimeter wave carriers(for instance, 30 GHz to 300 GHz), centimeter wave carriers (forinstance, 3 GHz to 30 GHz), and/or other frequency carriers can employan antenna array to provide beam formation and directivity fortransmission and/or reception of signals.

For example, in the illustrated embodiment, the communication system 110includes an array 102 of m×n antenna elements, which are each controlledby a separate signal conditioning circuit, in this embodiment. Asindicated by the ellipses, the communication system 110 can beimplemented with any suitable number of antenna elements and signalconditioning circuits.

With respect to signal transmission, the signal conditioning circuitscan provide transmit signals to the antenna array 102 such that signalsradiated from the antenna elements combine using constructive anddestructive interference to generate an aggregate transmit signalexhibiting beam-like qualities with more signal strength propagating ina given direction away from the antenna array 102.

In the context of signal reception, the signal conditioning circuitsprocess the received signals (for instance, by separately controllingreceived signal phases) such that more signal energy is received whenthe signal is arriving at the antenna array 102 from a particulardirection. Accordingly, the communication system 110 also providesdirectivity for reception of signals.

The relative concentration of signal energy into a transmit beam or areceive beam can be enhanced by increasing the size of the array. Forexample, with more signal energy focused into a transmit beam, thesignal is able to propagate for a longer range while providingsufficient signal level for RF communications. For instance, a signalwith a large proportion of signal energy focused into the transmit beamcan exhibit high effective isotropic radiated power (EIRP).

In the illustrated embodiment, the transceiver 105 provides transmitsignals to the signal conditioning circuits and processes signalsreceived from the signal conditioning circuits. As shown in FIG. 4A, thetransceiver 105 generates control signals for the signal conditioningcircuits. The control signals can be used for a variety of functions,such as controlling the gain and phase of transmitted and/or receivedsignals to control beamforming.

FIG. 4B is a schematic diagram of one example of beamforming to providea transmit beam. FIG. 4B illustrates a portion of a communication systemincluding a first signal conditioning circuit 114 a, a second signalconditioning circuit 114 b, a first antenna element 113 a, and a secondantenna element 113 b.

Although illustrated as included two antenna elements and two signalconditioning circuits, a communication system can include additionalantenna elements and/or signal conditioning circuits. For example, FIG.4B illustrates one embodiment of a portion of the communication system110 of FIG. 4A.

The first signal conditioning circuit 114 a includes a first phaseshifter 130 a, a first power amplifier 131 a, a first low noiseamplifier (LNA) 132 a, and switches for controlling selection of thepower amplifier 131 a or LNA 132 a. Additionally, the second signalconditioning circuit 114 b includes a second phase shifter 130 b, asecond power amplifier 131 b, a second LNA 132 b, and switches forcontrolling selection of the power amplifier 131 b or LNA 132 b.

Although one embodiment of signal conditioning circuits is shown, otherimplementations of signal conditioning circuits are possible. Forinstance, in one example, a signal conditioning circuit includes one ormore band filters, duplexers, and/or other components.

In the illustrated embodiment, the first antenna element 113 a and thesecond antenna element 113 b are separated by a distance d.Additionally, FIG. 4B has been annotated with an angle θ, which in thisexample has a value of about 90° when the transmit beam direction issubstantially perpendicular to a plane of the antenna array and a valueof about 0° when the transmit beam direction is substantially parallelto the plane of the antenna array.

By controlling the relative phase of the transmit signals provided tothe antenna elements 113 a, 113 b, a desired transmit beam angle θ canbe achieved. For example, when the first phase shifter 130 a has areference value of 0°, the second phase shifter 130 b can be controlledto provide a phase shift of about −2πf(d/ν)cos θ radians, where f is thefundamental frequency of the transmit signal, d is the distance betweenthe antenna elements, ν is the velocity of the radiated wave, and π isthe mathematic constant pi.

In certain implementations, the distance d is implemented to be about½λ, where λ is the wavelength of the fundamental component of thetransmit signal. In such implementations, the second phase shifter 130 bcan be controlled to provide a phase shift of about −π cos θ radians toachieve a transmit beam angle θ.

Accordingly, the relative phase of the phase shifters 130 a, 130 b canbe controlled to provide transmit beamforming. In certainimplementations, a baseband processor and/or a transceiver (for example,the transceiver 105 of FIG. 4A) controls phase values of one or morephase shifters and gain values of one or more controllable amplifiers tocontrol beamforming.

FIG. 4C is a schematic diagram of one example of beamforming to providea receive beam. FIG. 4C is similar to FIG. 4B, except that FIG. 4Cillustrates beamforming in the context of a receive beam rather than atransmit beam.

As shown in FIG. 4C, a relative phase difference between the first phaseshifter 130 a and the second phase shifter 130 b can be selected toabout equal to −2πf(d/ν)cos θ radians to achieve a desired receive beamangle θ. In implementations in which the distance d corresponds to about½λ, the phase difference can be selected to about equal to −π cos θradians to achieve a receive beam angle θ.

Although various equations for phase values to provide beamforming havebeen provided, other phase selection values are possible, such as phasevalues selected based on implementation of an antenna array,implementation of signal conditioning circuits, and/or a radioenvironment.

Examples of Integrated Doherty Power Amplifiers

Certain wireless communication systems, such as 5G systems, operate withrelatively high data rates, relative large capacity, and/or a relativelylarge number of users. Furthermore, such systems can include arelatively large number of power amplifiers for driving the antennaelements of an antenna array.

To enhance the integration of such systems, it is desirable for thepower amplifiers to operate with high efficiency (for instance, low DCpower consumption) and/or to be implemented with a compact design.

One type of power amplifier is a Doherty power amplifier, which includesa main or carrier amplification stage and an auxiliary or peakingamplification stage that operate in combination with one another toamplify an RF input signal. The Doherty power amplifier combines acarrier signal from the carrier amplification stage and a peaking signalfrom the peaking stage to generate an amplified RF output signal. Incertain implementations, the carrier amplification stage is enabled overa wide range of power levels while the peaking amplification stage isselectively enabled (for instance, by a class C bias circuit) at highpower levels.

Doherty power amplifiers include an output phase shifter and powercombiner for combining the carrier signal and the peaking signal. Theoutput phase shifter and power combiner increase component count and/orintroduce loss that degrades efficiency.

Provided herein are integrated Doherty power amplifiers that combine acarrier signal and a peaking signal using an antenna structure. Forexample, a multi-port antenna can be used to combine the carrier signaland the peaking signal, or separate antennas can operate in combinationwith one another to radiate a transmit wave in which the carrier signaland the peaking signal are combined. Accordingly, at least an outputcombining function of the Doherty power amplifier is implemented by theantenna structure rather than an explicit power combiner circuit.Furthermore, in certain implementations both the phase shifting andcombining functions of the output section of the Doherty power amplifierare implemented by way of the antenna structure rather than by includingan explicit phase shifting circuit and power combiner circuit.

For example, in certain embodiments, the Doherty power amplifierincludes a carrier amplification stage that generates a carrier signal,a peaking amplification stage that generates a peaking signal, and anantenna-based phase shifter and combiner for combining the carriersignal and the peaking signal. Accordingly, in such embodiments theoutput section of the Doherty power amplifier is integrated into theantenna structure. Not only does integrating the output section of theDoherty power amplifier into the antenna structure avoid a need for anexplicit phase shifter and power combiner, but also the Doherty poweramplifier can be matched directly to the antenna's impedance. Thisremoves additional matching components that would typically be presentat a Doherty power amplifier's output.

In certain implementations, the antenna-based phase shifter and combinerincludes a patch antenna including a first port that receives thecarrier signal and a second port that receives the peaking signal.Additionally, the patch antenna is implemented such that the carriersignal and the peaking signal combine with appropriate phase shift.Thus, rather than a conventional patch antenna with a single signalfeed, the patch antenna includes multiple signal feeds. Additionally,the input impedances of the first and second signal feeds areimplemented to provide equivalent impedance of the output section of theDoherty power amplifier, such that the carrier amplification stage andthe peaking amplification stage operate with appropriate outputimpedance.

The integrated Doherty power amplifiers herein exhibit low part count,which decreases cost and/or provides a more compact design. Furthermore,the Doherty power amplifiers can provide higher overall transmissionefficiency and/or lower DC power consumption, which in turn leads tolower operating temperatures and/or improved reliability.

In certain implementations, multiple peaking amplification stages areprovided. For example, two or more peaking amplification stages can beprovided and biased with different turn-on power thresholds.

The teachings herein are applicable to a wide variety of RFcommunication systems, including, but not limited to, base stations,network access points, mobile phones, tablets, customer-premisesequipment (CPE), laptops, computers, wearable electronics, and/or othercommunication devices.

As set forth further below, an analysis of one implementation of aDoherty power amplifier operating at 3.6 GHz and integrated with asingle patch antenna is provided. Using a relative permittivity (ε_(r))of 3.5, the patch antenna element had a simulated gain of 6.8 dBiwithout integration of the Doherty power amplifier. Additionally, withintegration of the Doherty power amplifier, a relatively small gainreduction of about 0.3 dB (about 6.8 dBi to about 6.4 dBi) was observed.Thus, integration of a Doherty power amplifier with an antenna structurecan also provide little to no impact on radiated gain.

FIG. 5 is a schematic diagram of an integrated Doherty power amplifier200 according to one embodiment. The integrated Doherty power amplifier200 includes a splitter and phase shifter 201, a carrier amplificationstage 205, a peaking amplification stage 206, and an antenna-based phaseshifter and combiner 209.

The splitter and phase shifter 201 operates to split an RF input signal(RF_IN) to generate a first RF signal to the carrier amplification stage205 and a second RF signal to the peaking amplification stage 206. Thesplitter and phase shifter 201 is also referred to herein as a splittingand phase shifting circuit. In certain implementations, the splitter andphase shifter 201 operates to output the first RF signal and the secondRF signal with about equal power and a phase shift of about ninetydegrees. For instance, in one example, the splitter and phase shifter201 is implemented as a 3 dB or hybrid coupler.

The carrier amplification stage 205 amplifies the first RF signal togenerate a carrier signal. Additionally, the peaking amplification stage201 amplifies the second RF signal to generate a peaking signal. In theillustrated embodiment, the antenna-based phase shifter and combiner 209receives the carrier signal and the peaking signal, and radiates atransmit wave.

Thus, the phase shifting and combining operations of the Doherty poweramplifier are provided by the antenna-based phase shifter and combiner209, rather than using an explicit phase shifting circuit and powercombiner circuit.

By implementing the Doherty power amplifier 200 in this manner, a numberof benefits can be achieved, including, but not limited to, lower partcount, lower cost, enhanced integration, and/or higher transmitefficiency. For example, not only does integrating phase shifting andcombining functions into the antenna-based phase shifter and combiner209 avoid a need for an explicit phase shifter and power combiner, butalso the carrier amplification stage 205 and/or the peakingamplification stage 206 can be matched directly to the impedance of theantenna-based phase shifter and combiner 209. Thus, elimination of phaseshifting circuitry, power combining circuitry, and/or output matchingcircuitry can be achieved.

FIG. 6A is a schematic diagram of an integrated Doherty power amplifier220 according to another embodiment. The integrated Doherty poweramplifier 220 includes a power splitter 221, a phase shifter 222, afirst attenuation component 223, a second attenuation component 224, acarrier amplification stage 225, and a peaking amplification stage 226.The integrated Doherty power amplifier 220 further includes a multi-portantenna 235 that serves as a phase shifter and combiner 229.

In the illustrated embodiment, the carrier amplification stage 225 isbiased by a first bias signal (BIAS1) and the peaking amplificationstage 226 is biased by a second bias signal (BIAS2). In certainimplementations, the first bias signal (BIAS1) enables the carrieramplification stage 225 over a wide range of power levels while thesecond bias signal (BIAS2) selectively enables the peaking amplificationstage 226 at high power levels. In one example, the second bias signal(BIAS2) is generated by a class C bias circuit.

As shown in FIG. 6A, the multi-port antenna 235 includes a first port P1that receives a carrier signal from the carrier amplification stage 225,and a second port P2 that receives a peaking signal from the peakingamplification stage 226.

The multi-port antenna 235 serves not only to wirelessly transmitsignals, but also to provide the functions of an output phase shifter231 and power combiner 232. By implementing the phase shifter andcombiner 229 using the multi-port antenna 235, enhanced integrationand/or higher transmit efficiency is achieved.

The multi-port antenna 235 includes the first port P1 and the secondport P2. The first port P1 and the second port P2 have different inputimpedance characteristics such that the multi-port antenna 235 providesthe equivalent functionality of the phase shifter and combiner 229. Forexample, the input impedances of the first port P1 and the second portP2 can be implemented to achieve a phase difference of about ninetydegrees between the first port P1 and the second port P2. Additionally,the phase shifted signals are combined via the antenna's ports, andwirelessly transmitted as an electromagnetic wave.

The multi-port antenna 235 can be implemented in a wide variety of ways.Examples of suitable antenna types of the multi-port antenna 235include, but are not limited to, a patch antenna, a dipole antenna, aceramic resonator antenna, a stamped metal antenna, or a laser directstructuring antenna.

FIG. 6B is a schematic diagram of an integrated Doherty power amplifier240 according to another embodiment. The integrated Doherty poweramplifier 240 includes a power splitter 221, a phase shifter 222, afirst attenuation component 223, a second attenuation component 224, acarrier amplification stage 225, and a peaking amplification stage 226.The integrated Doherty power amplifier 240 further includes a firstantenna 245 and a second antenna 246 that serve as a phase shifter andcombiner 229.

As shown in FIG. 6B, the first antenna 245 includes the first port P1,and the second antenna 246 includes the second port P2. The first portP1 and the second port P2 have different input impedance characteristicssuch that the first antenna 245 and the second antenna 246 provide theequivalent functionality of the phase shifter and combiner 229. Forexample, the input port P1 can provide a phase delay of about ninetydegrees relative to the second port P2, thereby replicating thefunctionality of the phase shifter 231.

Additionally, a first transmit wave from the first antenna 245 and asecond transmit wave from the second antenna 246 wirelessly combine viaconstructive interference to replicate the functionality of the powercombiner 232. For example, the aggregate transmit wave radiated from thefirst antenna 245 and the second antenna 246 can be combined in the farfield.

Examples of suitable antenna types for the first antenna 245 and thesecond antenna 246 include, but are not limited to, patch antennas,dipole antennas, ceramic resonator antennas, stamped metal antennas, orlaser direct structuring antennas.

FIG. 6C is a schematic diagram of an integrated Doherty power amplifier260 according to another embodiment. The integrated Doherty poweramplifier 260 includes a power splitter 221, a phase shifter 222, acarrier amplification stage 225, and peaking amplification stages 226 a,226 b, . . . 226 n. The integrated Doherty power amplifier 220 furtherincludes a multi-port antenna 255 that serves as a phase shifter andcombiner.

In the illustrated embodiment, the carrier amplification stage 225 isbiased by a first bias signal (BIAS1), while the peaking amplificationstages 226 a, 226 b, . . . 226 n are biased by second bias signals BIAS2a, BIAS2 b, . . . BIAS2 n. In certain implementations, the first biassignal (BIAS1) enables the carrier amplification stage 225 over a widerange of power levels while the second bias signals BIAS2 a, BIAS2 b, .. . BIAS2 n selectively enable the peaking amplification stages 226 a,226 b, . . . 226 n, respectively, at various high power levels orthresholds, which can vary from one another.

As shown in FIG. 6C, the multi-port antenna 255 includes a first port P1that receives a carrier signal from the carrier amplification stage 225and second ports P2 a, P2 b, . . . P2 n that receive peaking signalsfrom the peaking amplification stages 226 a, 226 b, . . . 226 n,respectively.

Although an embodiment with three peaking amplification stages isdepicted, the teachings herein are applicable to Doherty poweramplifiers with more or fewer peaking amplification stages.

The multi-port antenna 255 serves not only to wirelessly transmitsignals, but also to provide the functions of an output phase shifterand power combiner.

FIG. 6D is a schematic diagram of an integrated Doherty power amplifier270 according to another embodiment. The integrated Doherty poweramplifier 270 includes a power splitter 221, an input phase shifter 222,a carrier amplification stage 225, a peaking amplification stage 226,and an output phase shifter 231. The integrated Doherty power amplifier270 further includes a multi-port antenna 265 that serves as a combiner.

The output phase shifter 231 provides at least a portion of the outputphase shifting of the carrier signal from the carrier amplificationstage 225. In certain implementations, the multi-port antenna 265provides little to no phase shifting, and the output phase shifter 231provides a phase shift of about ninety degrees. In otherimplementations, the multi-port antenna 265 provides a first amount ofphase shifting (for instance, a coarse phase shift), while the outputphase shifter 231 provides a second amount of phase shift (for instance,a fine phase shift. The output phase shifter 231 can be implemented in awide variety of ways, including, but not limited to, using a varactorand/or other controllable capacitance components.

FIG. 6E is a schematic diagram of an integrated Doherty power amplifier280 according to another embodiment. The integrated Doherty poweramplifier 280 includes a power splitter 221, an input phase shifter 222,a carrier amplification stage 225, a peaking amplification stage 226, afirst output phase shifter 231, and a second output phase shifter 271.The integrated Doherty power amplifier 280 further includes a multi-portantenna 265 that serves as a combiner.

The integrated Doherty power amplifier 280 of FIG. 6E is similar to theintegrated Doherty power amplifier 270 of FIG. 6D, except that theintegrated Doherty power amplifier 280 includes multiple output phaseshifters. In particular, the integrated Doherty power amplifier 280includes the first output phase shifter 231 between the output of thecarrier amplification stage 225 and the first port of the multi-portantenna 265, and the second output phase shifter 271 between the outputof the peaking amplification stage 226 and the second port of themulti-port antenna 265.

The first output phase shifter 231 and the second output phase shifter271 operate to control the phase difference between the carrier signalreceived at the first port of the multi-port antenna 265 and the peakingsignal received at the second port of the multi-port antenna 265. Incertain implementations, the multi-port antenna 265 provides a firstamount of phase shifting (for instance, a coarse phase shift), while thefirst output phase shifter 231 and the second output phase shifter 271provide a second amount of phase shift (for instance, a fine phaseshift).

FIG. 6F is a schematic diagram of an integrated Doherty power amplifier290 according to another embodiment. The integrated Doherty poweramplifier 290 includes a power splitter 221, a first input phase shifter222, a second input phase shifter 282, a carrier amplification stage225, a peaking amplification stage 226, a first output phase shifter231, and a second output phase shifter 271. The integrated Doherty poweramplifier 290 further includes a multi-port antenna 265 that serves as acombiner.

The integrated Doherty power amplifier 290 of FIG. 6F is similar to theintegrated Doherty power amplifier 280 of FIG. 6E, except that theintegrated Doherty power amplifier 290 includes multiple input phaseshifters. In particular, the integrated Doherty power amplifier 290includes the first input phase shifter 222 between the power splitter221 and the input of the peaking amplification stage 226, and the secondinput phase shifter 282 between the power splitter 221 and the input ofthe carrier amplification stage 225. Including multiple input phaseshifters provides an additional degree of design flexibility.

FIG. 7A is an impedance model 300 of a multi-feed patch antenna 335according to one embodiment. As shown in FIG. 7A, the multi-feed patchantenna 335 includes a first port P1 and a second port P2. The impedancemodel 300 includes a first input termination resistor 301, a secondinput termination resistor 302, a first shunt capacitor 311, a secondshunt capacitor 312, a third shunt capacitor 313, a fourth shuntcapacitor 314, a first series inductor 321, a second series inductor322, and an output termination resistor 325.

In certain implementations herein, an antenna-based phase shifter andcombiner is implemented with impedance modifications and/ortransformations such that a peaking amplification stage and carrieramplification stage match into the antenna load. For example, a phaseshifter/combiner with a load impedance can be replaced with an antennaload. For instance, in one example, a 50 Ohm load is replaced by a 377Ohm load representing air.

FIGS. 7B-7D are simulation results of various performance parameters ofthe multi-feed patch antenna 335 of FIG. 7A generated based on theimpedance model 300 of FIG. 7A.

The simulation results correspond to a configuration of the impedancemodel 300 in which a resistance of the first input termination resistor301 is about 50 Ohm, a resistance of the second input terminationresistor 302 is about 50 Ohm, a capacitance of the first shunt capacitor311 is about 4 pF, a capacitance of the second shunt capacitor 312 isabout 4 pF, a capacitance of the third shunt capacitor 313 is about 35pF, a capacitance of the fourth shunt capacitor 314 is about 35 pF, aninductance of the first series inductor 321 is about 4 nH, an inductanceof the second series inductor 322 is about 35 nH, and a resistance ofthe output termination resistor 325 is about 377 Ohm.

FIG. 7B is one example of a Smith chart of S11 for the multi-feed patchantenna 335 of FIG. 7A. The Smith chart provides a graphicalillustration of reflection coefficient at port P1 of the multi-feedpatch antenna 335. The Smith chart was generated for a frequency sweepbetween 1 gigahertz (GHz) and 6 GHz.

FIG. 7C is one example of a Smith chart of S22 for the multi-feed patchantenna 335 of FIG. 7A. The Smith chart provides a graphicalillustration of reflection coefficient at port P2 of the multi-feedpatch antenna 335. The Smith chart was generated for a frequency sweepbetween 1 GHz and 6 GHz.

FIG. 7D is a graph of one example of isolation versus frequency for themulti-feed patch antenna of FIG. 7A. The graph depicts forwardtransmission in decibels (dB) versus frequency. As shown in FIG. 7D, anisolation between about 4 dB to 6 dB is achieved across a frequencyrange of 3 GHz to 3.8 GHz.

FIG. 7E is a graph of one example of phase shift versus frequency forthe multi-feed patch antenna of FIG. 7A. The graph depicts phase shiftbetween port P1 and port P2. As shown in FIG. 7E, a phase shift of90°±5° is provided across a frequency range of 3 GHz to 3.8 GHz.

FIG. 8A is a perspective view of a patch antenna with impedancetransformer 400 according to one embodiment. The patch antenna withimpedance transformer 400 includes a substrate 401 including a patchantenna element 402 and an impedance transformer 403 formed thereon.

The impedance transformer 403 includes a wide metal region 404 includinga first port P1 and a second port P2 for receiving a carrier signal anda peaking signal, respectively. The carrier signal and the peakingsignal can be provided in a wide variety of ways, such as using vias orelectromagnetic coupling from structures positioned beneath each port.The impedance transformer 403 further includes a narrow metal region 405of narrower width than the wide metal region 404.

As shown in FIG. 8A, the carrier signal and the peaking signal areprovided to the wide metal region 404, and propagate through the narrowmetal region 405 to reach the patch antenna element 402.

The difference in width between the wide metal region 404 and the narrowmetal region 405, the difference in width between the narrow metalregion 405 and the patch antenna element 402, and/or a relative distancefrom each port to the patch antenna element 402 provides an impedancetransformation.

The impedance transformation can provide a number of functions,including providing output matching to the carrier amplification stageand the peaking amplification stage that drive the first port P1 and thesecond port P2, respectively. For example, the impedance transformer 403can provide impedance modifications to provide matching into the patchantenna element 402.

Additionally, a difference in spacing between the first port P1 and thesecond port P2 provides a phase delay between the ports to achieve adesired amount of phase shift. For example, a phase shift of aboutninety degrees can be achieved over a desired range of frequencies byselecting a suitable spacing between the first port P1 and the secondport P2.

In certain implementations, the substrate 401 includes two or more metallayers, and the patch antenna element 402 and the impedance transformer403 are formed of metal on a first metal layer of the substrate 401.Additionally, at least one other metal layer of the substrate 401includes a ground plane that extends at least in part beneath the patchantenna element 402 and/or the impedance transformer 403.

FIG. 8B is a schematic diagram of a radiation pattern for the patchantenna with impedance transformer 400 of FIG. 8A. The radiation patternis simulated at a frequency of 3.6 GHz for an implementation in whichthe patch antenna 402 has a width of about 30.7 millimeters (mm) and alength of about 21.98 mm. As shown in FIG. 8B, the patch antenna withimpedance transformer 400 exhibits a relatively uniform radiationpattern, which is desirable in certain applications.

FIG. 9A is an impedance model 450 of the patch antenna with impedancetransformer 400 of FIG. 8A according to one embodiment. The impedancemodel 450 includes a first port P1, a second port P2, an inputtermination resistor 451, a first metal section 461, a second metalsection 462, a metal step 463, and a patch antenna section 464.

FIGS. 9B-9E are simulation results of various performance parameters ofthe patch antenna with impedance transformer 400 of FIG. 8A generatedbased on the impedance model 450 of FIG. 9A.

The simulation results correspond to a configuration of the impedancemodel 450 in which the input termination resistor 451 has a resistanceof about 50 Ohm, in which the metal section 461 has a width of about 2.3mm and a length of about 12.2 mm, in which the metal section 462 has awidth of about 0.6 mm and a length of about 6 mm, in which the metalstep 463 transitions from about 0.6 mm to about 30.7 mm, and in whichthe patch antenna section 464 has a width of about 30.7 mm and a lengthof about 21.98 mm.

FIG. 9B is one example of a Smith chart of S11 for the patch antennawith impedance transformer 400 of FIG. 8A. The Smith chart provides agraphical illustration of reflection coefficient at port P1 of the patchantenna with impedance transformer 400. The Smith chart was generatedfor a frequency sweep between 3 GHz and 4 GHz.

FIG. 9C is one example of a Smith chart of S22 for the patch antennawith impedance transformer 400 of FIG. 9A. The Smith chart provides agraphical illustration of reflection coefficient at port P2 of the patchantenna with impedance transformer 400. The Smith chart was generatedfor a frequency sweep between 3 GHz and 4 GHz.

FIG. 9D is a graph of one example of isolation versus frequency for thepatch antenna with impedance transformer 400 of FIG. 8A. The graphdepicts forward transmission in dB versus frequency.

FIG. 9E is a graph of one example of phase shift versus frequency forthe patch antenna with impedance transformer 400 of FIG. 8A. The graphdepicts phase shift between port P1 and port P2.

FIG. 10A is a perspective view of a multi-feed patch antenna 500according to one embodiment. The multi-feed patch antenna 500 includes apatch antenna element 501, a ground plane 502, and an impedancetransformer 503. FIG. 10B is a plan view of the impedance transformer503 of FIG. 10A.

Although not depicted in FIG. 10A, in certain implementations themulti-feed patch antenna 500 is implemented on a multi-layer substrate,such as a laminate. For example, the multi-feed patch antenna 500 can beimplemented in a substrate of a module, such as a packaged moduleincluding one or more semiconductor dies therein.

With reference to FIGS. 10A and 10B, the impedance transformer 503includes a feed conductor section 504 for electromagnetically couplingto the patch antenna element 501. The feed conductor section 504 iscoupled to the patch antenna element 501 by fields without a directelectrical connection, in this embodiment. The impedance transformer 503further includes a first input conductor 505 including a first stub 507and a first port P1. The impedance transformer 503 further includes asecond input conductor 506 including a second stub 508 and a second portP2.

The multi-feed patch antenna 500 includes impedance transformersintegrated under the patch antenna element 500 to provide a compactdesign. Additionally, the impedance transformer 503 is implemented toprovide separate impedance transformations for the first port P1 and thesecond port P2, thereby enhancing design flexibility.

In the illustrated embodiment, the impedance transformation provided tothe first port P1 is controlled by dimensions of the first inputconductor 505 and the first stub 507, while the impedance transformationprovided to the second port P2 is controlled by dimensions of the secondinput conductor 506 and the second stub 508.

By selecting different dimensions, a desired amount of impedancetransformation can be achieved for the first port P1 and the second portP2. Moreover, the impedance transformations need not be the same. Forinstance, in one example, a quarter wave impedance transformationbetween about 25 Ohm to 377 Ohm is provided for the first port P1, whilean impedance transformation between about 25 Ohm to 100 Ohm is providedfor the second port.

Providing different impedance transformations can aid in providingdesired impedances for different sections or stages of a Doherty poweramplifier. For instance, for the example above, the impedancetransformations provide enhanced performance for an implementation inwhich the peaking amplification stage operates with an impedance ofabout 25 Ohm, and in which the carrier amplification stage operates withan impedance of about 100 Ohm. Although an example of specific impedancevalues has been provided, desired impedances for a peaking amplificationstage and/or a carrier amplification stage can depend on a wide varietyof factors, including, but not limited to application and/orimplementation.

FIG. 10C is a schematic diagram of a radiation pattern for themulti-feed patch antenna 500 of FIG. 10A. The radiation pattern issimulated at a frequency of 3.6 GHz for one implementation of themulti-feed patch antenna 500. As shown in FIG. 10C, the multi-feed patchantenna 500 exhibits a relatively uniform radiation pattern, which isdesirable in certain applications.

FIG. 11A is one example of a Smith chart of S11 for the multi-feed patchantenna 500 of FIG. 10A. The Smith chart provides a graphicalillustration of reflection coefficient at port P1 of the multi-feedpatch antenna 500. The Smith chart was generated for a frequency sweepbetween 3 GHz and 4 GHz.

FIG. 11B is one example of a Smith chart of S22 for the multi-feed patchantenna 500 of FIG. 10A. The Smith chart provides a graphicalillustration of reflection coefficient at port P2 of the multi-feedpatch antenna 500. The Smith chart was generated for a frequency sweepbetween 3 GHz and 6 GHz

FIG. 11C is a graph of one example of isolation versus frequency for themulti-feed patch antenna 500 of FIG. 10A. The graph depicts forwardtransmission in dB versus frequency.

FIG. 11D is a graph of one example of phase shift versus frequency forthe multi-feed patch antenna 500 of FIG. 10A. The graph depicts phaseshift between port P1 and port P2.

Although various examples of simulation results have been shown,simulation results can vary based on a wide variety of factors,including, but not limited to, simulation parameters (includingoperating frequency), antenna models, and/or simulation tools.

Examples of Modules and Devices Applicable to Integrated Doherty PowerAmplifiers

Integrated Doherty power amplifiers can be implemented using a widevariety of modules, semiconductor dies, and/or other components.Furthermore, integrated Doherty power amplifiers can be included a widevariety of devices, including, but not limited to, mobile phones,tablets, base stations, network access points, customer-premisesequipment (CPE), laptops, and wearable electronics. For example,modules, semiconductor dies, and/or other components can be included oncircuit boards used in such devices.

FIG. 12 is a schematic diagram of one embodiment of a module 680. Themodule 680 includes antenna array(s) 681, a substrate 682, encapsulation683, IC(s) 684, surface mound device(s) or SMD(s) 685, integratedpassive device(s) or IPD(s) 686, and shielding 687. The module 680illustrates various examples of components and structures that can beincluded in a module of a communication device that includes one or moreintegrated Doherty power amplifiers.

Although one example of a combination of components and structures isshown, a module can include more or fewer components and/or structures.

FIG. 13A is a perspective view of another embodiment of a module 700.FIG. 13B is a cross-section of the module 700 of FIG. 13A taken alongthe lines 13B-13B.

The module 700 includes a laminated substrate or laminate 701, asemiconductor die or IC 702 (not visible in FIG. 13A), SMDs (not visiblein FIG. 13A), and an antenna array including antenna elements 710 a 1,710 a 2, 710 a 3 . . . 710 an, 710 b 1, 710 b 2, 710 b 3 . . . 710 bn,710 c 1, 710 c 2, 710 c 3 . . . 710 cn, 710 m 1, 710 m 2, 710 m 3 . . .710 mn.

Although not shown in FIGS. 13A and 13B, the module 700 can includeadditional structures and components that have been omitted from thefigures for clarity. Moreover, the module 700 can be modified or adaptedin a wide variety of ways as desired for a particular application and/orimplementation.

The antenna elements antenna elements 710 a 1, 710 a 2, 710 a 3 . . .710 an, 710 b 1, 710 b 2, 710 b 3 . . . 710 bn, 710 c 1, 710 c 2, 710 c3 . . . 710 cn, 710 m 1, 710 m 2, 710 m 3 . . . 710 mn are formed on afirst surface of the laminate 701, and can be used to receive and/ortransmit signals, based on implementation. Although a 4×4 array ofantenna elements is shown, more or fewer antenna elements are possibleas indicated by ellipses. Moreover, antenna elements can be arrayed inother patterns or configurations, including, for instance, arrays usingnon-uniform arrangements of antenna elements. Furthermore, in anotherembodiment, multiple antenna arrays are provided, such as separateantenna arrays for transmit and receive.

In the illustrated embodiment, the IC 702 is on a second surface of thelaminate 701 opposite the first surface. However, other implementationsare possible. In one example, the IC 702 is integrated internally to thelaminate 701.

In certain implementations, the IC 702 includes one or more integratedDoherty power amplifiers associated with one or more of the antennaelements 710 a 1, 710 a 2, 710 a 3 . . . 710 an, 710 b 1, 710 b 2, 710 b3 . . . 710 bn, 710 c 1, 710 c 2, 710 c 3 . . . 710 cn, 710 m 1, 710 m2, 710 m 3 . . . 710 mn. Although an implementation with onesemiconductor chip is shown, the teachings herein are applicable toimplementations with additional chips.

The laminate 701 can include various structures including, for example,conductive layers, dielectric layers, and/or solder masks. The number oflayers, layer thicknesses, and materials used to form the layers can beselected based on a wide variety of factors, and can vary withapplication and/or implementation. The laminate 701 can include vias forproviding electrical connections to signal feeds and/or ground feeds ofthe antenna elements. For example, in certain implementations, vias canaid in providing electrical connections between Doherty power amplifiersof the IC 702 and corresponding antenna elements.

The antenna elements 710 a 1, 710 a 2, 710 a 3 . . . 710 an, 710 b 1,710 b 2, 710 b 3 . . . 710 bn, 710 c 1, 710 c 2, 710 c 3 . . . 710 cn,710 m 1, 710 m 2, 710 m 3 . . . 710 mn can correspond to antennaelements implemented in a wide variety of ways. In one example, thearray of antenna elements includes patch antenna elements formed from apatterned conductive layer on the first side of the laminate 701, with aground plane formed using a conductive layer on opposing side of thelaminate 701 or internal to the laminate 701. Other examples of antennaelements include, but are not limited to, dipole antenna elements,ceramic resonators, stamped metal antennas, and/or laser directstructuring antennas.

FIG. 14 is a schematic diagram of one embodiment of a mobile device 800.The mobile device 800 includes a baseband system 801, a transceiver 802,a front end system 803, antennas 804, a power management system 805, amemory 806, a user interface 807, and a battery 808.

The mobile device 800 can be used communicate using a wide variety ofcommunications technologies, including, but not limited to, 2G, 3G, 4G(including LTE, LTE-Advanced, and LTE-Advanced Pro), 5G NR, WLAN (forinstance, WiFi), WPAN (for instance, Bluetooth and ZigBee), WMAN (forinstance, WiMax), and/or GPS technologies.

The transceiver 802 generates RF signals for transmission and processesincoming RF signals received from the antennas 804. It will beunderstood that various functionalities associated with the transmissionand receiving of RF signals can be achieved by one or more componentsthat are collectively represented in FIG. 14 as the transceiver 802. Inone example, separate components (for instance, separate circuits ordies) can be provided for handling certain types of RF signals.

The front end system 803 aids is conditioning signals transmitted toand/or received from the antennas 804. In the illustrated embodiment,the front end system 803 includes antenna tuning circuitry 810, poweramplifiers (PAs) 811, low noise amplifiers (LNAs) 812, filters 813,switches 814, and signal splitting/combining circuitry 815. One or moreof the power amplifiers 811 can be implemented as an integrated Dohertypower amplifier in accordance with the teachings herein. Although oneexample of front end components is shown, other implementations arepossible.

For example, the front end system 803 can provide a number offunctionalities, including, but not limited to, amplifying signals fortransmission, amplifying received signals, filtering signals, switchingbetween different bands, switching between different power modes,switching between transmission and receiving modes, duplexing ofsignals, multiplexing of signals (for instance, diplexing ortriplexing), or some combination thereof.

In certain implementations, the mobile device 800 supports carrieraggregation, thereby providing flexibility to increase peak data rates.Carrier aggregation can be used for both Frequency Division Duplexing(FDD) and Time Division Duplexing (TDD), and may be used to aggregate aplurality of carriers or channels. Carrier aggregation includescontiguous aggregation, in which contiguous carriers within the sameoperating frequency band are aggregated. Carrier aggregation can also benon-contiguous, and can include carriers separated in frequency within acommon band or in different bands.

The antennas 804 can include antennas used for a wide variety of typesof communications. For example, the antennas 804 can include antennasfor transmitting and/or receiving signals associated with a wide varietyof frequencies and communications standards.

In certain implementations, the antennas 804 support MIMO communicationsand/or switched diversity communications. For example, MIMOcommunications use multiple antennas for communicating multiple datastreams over a single radio frequency channel. MIMO communicationsbenefit from higher signal to noise ratio, improved coding, and/orreduced signal interference due to spatial multiplexing differences ofthe radio environment. Switched diversity refers to communications inwhich a particular antenna is selected for operation at a particulartime. For example, a switch can be used to select a particular antennafrom a group of antennas based on a variety of factors, such as anobserved bit error rate and/or a signal strength indicator.

The mobile device 800 can operate with beamforming in certainimplementations. For example, the front end system 803 can includeamplifiers having controllable gain and phase shifters havingcontrollable phase to provide beam formation and directivity fortransmission and/or reception of signals using the antennas 804. Forexample, in the context of signal transmission, the amplitude and phasesof the transmit signals provided to the antennas 804 are controlled suchthat radiated signals from the antennas 804 combine using constructiveand destructive interference to generate an aggregate transmit signalexhibiting beam-like qualities with more signal strength propagating ina given direction. In the context of signal reception, the amplitude andphases are controlled such that more signal energy is received when thesignal is arriving to the antennas 804 from a particular direction. Incertain implementations, the antennas 804 include one or more arrays ofantenna elements to enhance beamforming.

The baseband system 801 is coupled to the user interface 807 tofacilitate processing of various user input and output (I/O), such asvoice and data. The baseband system 801 provides the transceiver 802with digital representations of transmit signals, which the transceiver802 processes to generate RF signals for transmission. The basebandsystem 801 also processes digital representations of received signalsprovided by the transceiver 802. As shown in FIG. 14, the basebandsystem 801 is coupled to the memory 806 of facilitate operation of themobile device 800.

The memory 806 can be used for a wide variety of purposes, such asstoring data and/or instructions to facilitate the operation of themobile device 800 and/or to provide storage of user information.

The power management system 805 provides a number of power managementfunctions of the mobile device 800. In certain implementations, thepower management system 805 includes a PA supply control circuit thatcontrols the supply voltages of the power amplifiers 811. For example,the power management system 805 can be configured to change the supplyvoltage(s) provided to one or more of the power amplifiers 811 toimprove efficiency, such as power added efficiency (PAE).

As shown in FIG. 14, the power management system 805 receives a batteryvoltage from the battery 808. The battery 808 can be any suitablebattery for use in the mobile device 800, including, for example, alithium-ion battery.

FIG. 15 is a schematic diagram of a power amplifier system 860 accordingto one embodiment. The illustrated power amplifier system 860 includes abaseband processor 841, a transmitter/observation receiver 842, asplitter and phase shifter 201, a carrier amplification stage 205, apeaking amplification stage 206, an antenna-based phase shifter andcombiner 209, a directional coupler 844, a PA bias control circuit 847,and a PA supply control circuit 848. The illustratedtransmitter/observation receiver 842 includes an I/Q modulator 857, amixer 858, and an analog-to-digital converter (ADC) 859. In certainimplementations, the transmitter/observation receiver 842 isincorporated into a transceiver.

The baseband processor 841 can be used to generate an in-phase (I)signal and a quadrature-phase (Q) signal, which can be used to representa sinusoidal wave or signal of a desired amplitude, frequency, andphase. For example, the I signal can be used to represent an in-phasecomponent of the sinusoidal wave and the Q signal can be used torepresent a quadrature-phase component of the sinusoidal wave, which canbe an equivalent representation of the sinusoidal wave. In certainimplementations, the I and Q signals can be provided to the I/Qmodulator 857 in a digital format. The baseband processor 841 can be anysuitable processor configured to process a baseband signal. Forinstance, the baseband processor 841 can include a digital signalprocessor, a microprocessor, a programmable core, or any combinationthereof. Moreover, in some implementations, two or more basebandprocessors 841 can be included in the power amplifier system 860.

The I/Q modulator 857 can be configured to receive the I and Q signalsfrom the baseband processor 841 and to process the I and Q signals togenerate an RF input signal. For example, the I/Q modulator 857 caninclude digital-to-analog converters (DACs) configured to convert the Iand Q signals into an analog format, mixers for upconverting the I and Qsignals to RF, and a signal combiner for combining the upconverted I andQ signals into an RF input signal. In certain implementations, the I/Qmodulator 857 can include one or more filters configured to filterfrequency content of signals processed therein.

The splitter and phase shifter 201 receives the RF input signal from theI/Q modulator 857, and generates a first RF signal for the carrieramplification stage 205 and a second RF signal for the peakingamplification stage 206.

In the illustrated embodiment, the directional coupler 844 senses anoutput signal of the carrier amplification stage 205. Additionally, thesensed output signal from the directional coupler 844 is provided to themixer 858, which multiplies the sensed output signal by a referencesignal of a controlled frequency. The mixer 858 operates to generate adownshifted signal by downshifting the sensed output signal's frequencycontent. The downshifted signal can be provided to the ADC 859, whichcan convert the downshifted signal to a digital format suitable forprocessing by the baseband processor 841.

Including a feedback path from the output of one or more amplificationstages of a Doherty power amplifier to the baseband processor 841 canprovide a number of advantages. For example, implementing the basebandprocessor 841 in this manner can aid in providing power control,compensating for transmitter impairments, and/or in performing digitalpre-distortion (DPD). Although one example of a sensing path for aDoherty power amplifier is shown, other implementations are possible.For instance, in another example, a multiplexed sensing path or separatesensing paths are provided for the carrier amplification stage 205 andthe peaking amplification stage 206.

The PA supply control circuit 848 receives a power control signal fromthe baseband processor 841, and controls the power amplifier supplyvoltage V_(CC) provided to the carrier amplification stage 205 and thepeaking amplification stage 206. The PA supply control circuit 848 cancontrol the voltage level of the power amplifier supply voltage V_(CC)to enhance the power amplifier system's PAE.

The PA supply control circuit 848 can employ various power managementtechniques to change the voltage level of one or more of the supplyvoltages over time to improve the power amplifier's power addedefficiency (PAE), thereby reducing power dissipation.

One technique for improving efficiency of a power amplifier is averagepower tracking (APT), in which a DC-to-DC converter is used to generatea supply voltage for a power amplifier based on the power amplifier'saverage output power. Another technique for improving efficiency of apower amplifier is envelope tracking (ET), in which a supply voltage ofthe power amplifier is controlled in relation to the envelope of the RFinput signal. Thus, when a voltage level of the envelope of the RF inputsignal increases the voltage level of the power amplifier's supplyvoltage can be increased. Likewise, when the voltage level of theenvelope of the RF input signal decreases the voltage level of the poweramplifier's supply voltage can be decreased to reduce power consumption.

In certain configurations, the PA supply control circuit 848 is amulti-mode supply control circuit that can operate in multiple supplycontrol modes including an APT mode and an ET mode. For example, thepower control signal from the baseband processor 841 can instruct the PAsupply control circuit 848 to operate in a particular supply controlmode.

As shown in FIG. 15, the PA bias control circuit 847 receives a biascontrol signal from the baseband processor 841, and generates a firstbias signal for the carrier amplification stage 205 and a second biassignal for the peaking amplification stage 206. In certainimplementations, the carrier amplification stage 205 is enabled over awide range of power levels while the peaking amplification stage 206 isselectively enabled (for instance, by class C bias circuitry of the PAbias control circuit 847) at high power levels.

FIG. 16A is a schematic diagram of another embodiment of a module 900.FIG. 16B is a schematic diagram of a cross-section of the module 900 ofFIG. 16A taken along the lines 16B-16B.

The module 900 includes radio frequency components 901, a semiconductordie 902, surface mount devices 903, wirebonds 908, a package substrate920, and an encapsulation structure 940. The package substrate 920includes pads 906 formed from conductors disposed therein. Additionally,the semiconductor die 902 includes pins or pads 904, and the wirebonds908 have been used to connect the pads 904 of the die 902 to the pads906 of the package substrate 920.

The semiconductor die 902 includes a splitter and phase shifter 201, acarrier amplification stage 205, and a peaking amplification stage 206,which can be implemented in accordance with one or more featuresdisclosed herein. In certain implementations, an antenna-based phaseshifter and combiner or other antenna structure is attached to thepackaging substrate 920, and receives a carrier signal from the carrieramplification stage 205 and a peaking signal from the peakingamplification stage 206.

The packaging substrate 920 can be configured to receive a plurality ofcomponents such as radio frequency components 901, the semiconductor die902 and the surface mount devices 903, which can include, for example,surface mount capacitors and/or inductors. In one implementation, theradio frequency components 901 include integrated passive devices(IPDs).

As shown in FIG. 16B, the module 900 is shown to include a plurality ofcontact pads 932 disposed on the side of the module 900 opposite theside used to mount the semiconductor die 902. Configuring the module 900in this manner can aid in connecting the module 900 to a circuit board,such as a phone board of a mobile device. The example contact pads 932can be configured to provide radio frequency signals, bias signals,and/or power (for example, a power supply voltage and ground) to thesemiconductor die 902 and/or other components. As shown in FIG. 16B, theelectrical connections between the contact pads 932 and thesemiconductor die 902 can be facilitated by connections 933 through thepackage substrate 920. The connections 933 can represent electricalpaths formed through the package substrate 920, such as connectionsassociated with vias and conductors of a multilayer laminated packagesubstrate.

In some embodiments, the module 900 can also include one or morepackaging structures to, for example, provide protection and/orfacilitate handling. Such a packaging structure can include overmold orencapsulation structure 940 formed over the packaging substrate 920 andthe components and die(s) disposed thereon.

It will be understood that although the module 900 is described in thecontext of electrical connections based on wirebonds, one or morefeatures of the present disclosure can also be implemented in otherpackaging configurations, including, for example, flip-chipconfigurations.

CONCLUSION

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The word “coupled”, as generally usedherein, refers to two or more elements that may be either directlyconnected, or connected by way of one or more intermediate elements.Likewise, the word “connected”, as generally used herein, refers to twoor more elements that may be either directly connected, or connected byway of one or more intermediate elements. Additionally, the words“herein,” “above,” “below,” and words of similar import, when used inthis application, shall refer to this application as a whole and not toany particular portions of this application. Where the context permits,words in the above Detailed Description using the singular or pluralnumber may also include the plural or singular number respectively. Theword “or” in reference to a list of two or more items, that word coversall of the following interpretations of the word: any of the items inthe list, all of the items in the list, and any combination of the itemsin the list.

Moreover, conditional language used herein, such as, among others,“may,” “could,” “might,” “can,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or withoutauthor input or prompting, whether these features, elements and/orstates are included or are to be performed in any particular embodiment.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the disclosure. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the disclosure. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the disclosure.

What is claimed is:
 1. An integrated Doherty power amplifier comprising:a splitting and phase shifting circuit configured to receive a radiofrequency input signal, and to output a first radio frequency signal anda second radio frequency signal; a carrier amplification stageconfigured to generate a carrier signal based on amplifying the firstradio frequency signal; a peaking amplification stage configured togenerate a peaking signal based on amplifying the second radio frequencysignal; and an antenna structure configured to combine the carriersignal and the peaking signal, and to radiate a transmit wave in whichthe carrier signal and the peaking signal are combined with a phaseshift.
 2. The integrated Doherty power amplifier of claim 1 wherein theantenna structure includes a first port configured to receive thecarrier signal and a second port configured to receive the peakingsignal.
 3. The integrated Doherty power amplifier of claim 2 wherein thecarrier amplification stage matches into an impedance of the first port,and the peaking amplification stage matches into an impedance of thesecond port.
 4. The integrated Doherty power amplifier of claim 2wherein the first port provides a first impedance transformation, andthe second port provides a second impedance transformation differentfrom the first impedance transformation.
 5. The integrated Doherty poweramplifier of claim 2 wherein the antenna structure includes a patchantenna element, and an impedance transformer having a first metalregion and a second metal region of different widths, the second metalregion connecting the first metal region to the patch antenna element.6. The integrated Doherty power amplifier of claim 5 wherein the firstmetal region includes the first port and the second port, the secondmetal region of narrower width than the first metal region.
 7. Theintegrated Doherty power amplifier of claim 5 wherein a distance betweenthe first port and the second port provides a phase shift of aboutninety degrees at a frequency of the transmit wave.
 8. The integratedDoherty power amplifier of claim 2 wherein the antenna structureincludes a patch antenna element, and an impedance transformer includinga feed conductor coupled to the patch antenna element, a first inputconductor extending from the feed conductor and including the firstport, and a second input conductor extending from the feed conductor andincluding the second port.
 9. The integrated Doherty power amplifier ofclaim 1 wherein the antenna structure provides the phase shift.
 10. Theintegrated Doherty power amplifier of claim 1 further comprising anoutput phase shifter configured to provide at least a portion of thephase shift.
 11. The integrated Doherty power amplifier of claim 1wherein the first radio frequency signal and the second radio frequencysignal have about equal power and a phase difference of about ninetydegrees.
 12. A mobile device comprising: a transceiver configured togenerate a radio frequency input signal; a Doherty power amplifierconfigured to amplify the radio frequency input signal, the Dohertypower amplifier including a carrier amplification stage configured tooutput a carrier signal and a peaking amplification stage configured tooutput a peaking signal; and an antenna structure configured to combinethe carrier signal and the peaking signal, and to radiate a transmitwave in which the carrier signal and the peaking signal are combinedwith a phase shift.
 13. The mobile device of claim 12 wherein theantenna structure includes a first port configured to receive thecarrier signal and a second port configured to receive the peakingsignal.
 14. The mobile device of claim 13 wherein the first portprovides a first impedance transformation, and the second port providesa second impedance transformation different from the first impedancetransformation.
 15. The mobile device of claim 13 wherein the antennastructure includes a patch antenna element, and an impedance transformerhaving a first metal region and a second metal region of differentwidths, the second metal region connecting the first metal region to thepatch antenna element.
 16. The mobile device of claim 15 wherein theimpedance transformer includes a first metal region and a second metalregion of different widths, the second metal region connecting the firstmetal region to the patch antenna element, and the first metal regionincluding the first port and the second port.
 17. The mobile device ofclaim 13 wherein the antenna structure includes a patch antenna element,and an impedance transformer including a feed conductor coupled to thepatch antenna element, a first input conductor extending from the feedconductor and including the first port, and a second input conductorextending from the feed conductor and including the second port.
 18. Aradio frequency module comprising: a substrate; a semiconductor dieattached to the substrate and including a Doherty power amplifierconfigured to amplify a radio frequency input signal, the Doherty poweramplifier including a carrier amplification stage configured to generatea carrier signal and a peaking amplification stage configured togenerate a peaking signal; and an antenna structure attached to thesubstrate and configured to combine the carrier signal and the peakingsignal, the antenna structure configured to radiate a transmit wave inwhich the carrier signal and the peaking signal are combined with aphase shift.
 19. The radio frequency module of claim 18 wherein theantenna structure includes a first port configured to receive thecarrier signal and a second port configured to receive the peakingsignal.
 20. The radio frequency module of claim 19 wherein the firstport provides a first impedance transformation, and the second portprovides a second impedance transformation different from the firstimpedance transformation.